If it were not for double standards, the Left wouldn't have any.
Of course they first accuse others of what they, themselves, are doing.
It forces others to prove they didn't. (Tough logical position).
If (rightfully) accused of the same thing, which they usually are indeed guilty of, they can always say the accusation is just because they 'outed' the opposition.
That argument is easily spun into an "I know you are but what am I" sort of juvenile exchange, and the worst outcome for the Left is that the public loses interest at people yammering talking points over top of each other.